Contactless/proximity communication systems represented by an IC card have become widespread because they can be simply and conveniently manipulated. The IC card is ordinarily used by a user in such a manner that the user approaches the IC card to a card reading/writing device. The card reading/writing device polls an IC card at all times, and when it discovers an external IC card, a communication operation starts between the card reading/writing device and the external IC card. When, for example, a private code and other individual authentification information, the value information of an electronic ticket and the like are stored to an IC card, authentification processing for visitors and passengers can be executed in a cash dispenser, an entrance door of a concert hall, a ticket gate of a station, and the like.
Recently, as a miniaturization technology is improved, an IC card having a relatively large amount of memory capacity appears. According to an IC card having a large amount of memory capacity, one IC card can be used to a plurality of applications by extending a file system on a memory space and storing a plurality of applications at the same time. When, for example, a plurality of applications such as electronic money for executing electronic settlement, an electronic ticket for coming in a particular concert hall, and the like are stored on one IC card, the one IC card can be applied to various applications. The electronic money and the electronic ticket to which reference is made here indicate a construction which is settled (electronically) through electronic data issued according to a fund presented by a user or the electronic data itself.
Further, the IC card and the card reader/writer (card reading/writing device), which includes a wired interface to be connected to an external equipment in addition to the wireless and contactless interface, can be used by being built in respective equipments such as a mobile terminal, PDA (Personal Digital Assistance), CE (Consumer Electronics) equipment, personal computer, and the like. That is, when these equipments are provided with the function of any one or both of the IC card and the card reading/writing device, it is possible to execute a general-purpose bidirectional proximity data communication using a contactless communication technology making use of the IC card. Since an IC card technology has a tamper resistance because it is difficult to copy or alter the information in an IC card, this kind of proximity data communication can realize high-level security.
There is proposed, for example, a communication system among three components which is executed between a card reading/writing device and an information processing terminal, which is connected to an IC card or an IC chip through a wired interface, by interposing the IC card or the IC chip therebetween (refer to, for example, Patent Document 1). In the system, a data communication is executed among the reading/writing device, a program controller disposed in the information processing terminal, a wireless communication interface built in the information processing terminal for executing a wireless communication to the reading/writing device, a wired communication interface to be connected to the program controller, and the IC card with a memory.
The IC chip built in the information processing terminal has a wireless communication mode for executing transaction through the wireless communication interface in response to the carrier wave detected from the reading/writing device and a wired communication mode for executing transaction through the wired communication interface in response to the start of an internal power supply in the information processing terminal. In the wired communication mode, the program controller of the information processing terminal can issue an activate command for temporarily switching the wired communication mode to the wireless communication mode and a not activate command for returning the wireless communication mode, which is temporarily made effective, to the wired communication mode. On the other hand, in the wireless communication mode, an external card reading/writing device issues a second activate command for temporarily switching the wireless communication mode to the wired communication mode and a second not activate command for returning the wired communication mode, which is temporarily made effective, to the wireless communication mode.
In the wired communication mode, after the information processing terminal issues the activate command, temporarily shifts to the wireless communication mode, and writes data from the external card reading/writing device to the IC chip, it issues the not activate command this time, returns to the wired communication mode, and reads the data written to the IC chip to thereby transmit the data from the external card reading/writing device to the information processing terminal through the IC card. Further, after the information processing terminal writes data to the IC card, it issues the activate command, temporarily shifts to the wireless communication mode. Then, after the external card reading/writing device reads the data from the IC chip, the information processing terminal issues the not activate command this time and returns to the wired communication mode to thereby transmit the data therefrom to the external card reading/writing device through the IC card.
On the other hand, in the wireless communication mode, the external card reading/writing device issues the second activate command, temporarily shifts to the wired communication mode, and writes data from the information processing terminal to the IC chip. Then, the external card reading/writing device issues the second not activate command this time, returns to the wireless communication mode, and reads the data written to the IC chip to thereby transmit the data from the information processing terminal to the external card reading/writing device through the IC card. Further, after the external card reading/writing device writes data to the IC card, it issues the second activate command, temporarily shifts to the wired communication mode. Then, after the information processing terminal reads the data from the IC chip, the external card reading/writing device issues the second not activate command this time and returns to the wireless communication mode to thereby transmit the data from the external card reading/writing device to the information processing terminal through the IC card.
According to the communication system as described above, a secure data communication can be realized between an equipment having a card reading/writing function and the information processing terminal connected to the IC card through wire making use of a contactless data communication path realized by interposing the IC card.
On the other hand, since a conventional contactless IC card communication protocol employs such a procedure that when a command is transmitted, a response is received, it is not suitable to transmit a relatively large amount of data such as image data at high speed although it is suitable to securely transfer relatively short text data such as URL (Uniform Resource Locator).
Further, when it is considered to send data from the card reading/writing device side to the information processing terminal side, the interposed IC card does not have a mechanism for notifying that the data transmitted to the information processing terminal is received by the contactless interface through the wired interface. Accordingly, since the information processing terminal can not detect or confirm at once whether or not the IC card receives the data sent to it, a problem arises also in that it is difficult to synchronize transmitted data on the card reading/writing device side.    Patent Document 1: Japanese Unexamined Patent Application Publication No. 2003-203212